Computing device.



UNITED STATES I FATENT OFFICE.

COMPUTING' DEVICE.

Specification of Letters Patent.

Patented June 11, 1907.

Application filed April 28, 1904- Serial N0. 205,378.

To all whom zlt may concern:

Be it known that I, CHARLES W. DRAPER, of Washington, District ofColumbia, have invented a new and useful Computing Device, whichinvention is fully set forth in the following specification.

My invention relates to devices for computing interest, wages, or thecost of a designated quantity of any commodity at a designated rate ofcharge, and particularly to that class of such devices wherein afinder-slide and a table, the latter having printed thereon numbersrepresenting numerous results, are relatively movable to facilitatefinding of the particular result of certain given factors.

M y present invention comprises improvements in the finder-slide, and inthe arrangement of the numbers representing the'results and factorsthereof, whereby the number on the table representing the particularresult sought can. be quickly located by minimum movement of the slideand effort on the part of the operator and without danger ofconfugion-with numbers representing other resu ts.

My invention also comprises other features of improvement, all of whichwill be readily understood by reference to the accompanying drawings,illustrating several of the many possible forms in which the inventionmay be embodied.

Figure 1 is a plan view, and Fig. 2 a transverse section on line 22, ofFig. 1, of one embodiment; Figs. 3 and 5 are plan views,-

and Fig. 4 a transverse section on line 4 4 of Fig. 3, of anotherembodiment; Figs. 6 and 7 are fragmentary views illustratingimprovements in details. v

Referring to Figs. 1 and 2, A is a shallow receptacle or tray adapted toreceive a number of tables a. Each table comprises a plate or sheet,preferably of stiff paper, cardward, or other suitable material, havingfigures representing numerous results thereon, preferably on both sides.he tray shown in Fig. 2 contains four tables, the upper face of thetopmost table bearing, as shown in Fig. 1, numbers representing theinterest on from $1. to to days. v turned over or other tables broughtto the top to expose tables at other rates of interest. B is a framehinged at b to tray A, and adapted to be secured in its closed positionby any suitable catchsuch as a spring b engaging a knob b rinted $9. at6% for from 1 l The uppermost table may be C is a finder-slide adaptedto move freely in grooves c, c, in the inner edges of the frame B; aknob a may be gripped for im parting the movement. As shown, the slideis of such width as to cover a large portion of the underlying table andis provided with two transverse beveled slots d, d near its upper andlower edges, respectively. Numers on the upper half of the table areintended to be read through the slot (1, and those on the lower half,through the slot d By locating these slots at the roper distance apartrelative to the lines o figures on the table, it is possible to exposeevery figure on the table through one or the other slot by moving'theslide a distance equal to but onehalf the length of the space covered bythe figures on the table. It follows that by using two widely separatedslots movement of the slide necessary to cover the whole table isgreatly reduced and may be reduced to a minimum. Furthermore, theemployment of an-expansive slide obscures from view a large part of thenumbers on the table, and particularly all but those which arerelatively remote from the transverse line of figures in which the onedesired appears. Confusion of vision is thus avoided. Strain upon theeyes may be further relieved by making the finder green.

In Figs. 3, 4' and .5, I have shown a cheaper and simpler embodiment ofthe invention. D, D are two tables, preferably of stiff paper orcard-board, and E is the finder-slide passing completely around thetables, the finder and tables being relatively movable. In manipulatingthis form of the invention it hold the fixed and to impart movement tothe tables. The wide finder depends over or extends across and bearsagainst the two parallel side edges of the table or tables and initsmovement is accurately guided by said edges. Preferably the finder hastwo slots 0, e through both sides thereof fFig. 4) and the tables areprinted on both sides so that they can beremoved from the finder i andtuned over. The capacity of the device is thus greatlyincreased. Annumber of tables may beemployed,--and, i desired, the 1 slots 6, e maybe omitted from one sidgof the Efinder. For certain uses of theinvention (hereafter explained) openings f, are i placed at one end ofthe slots 0, erespectively; these openings may form continual tions ofthe 'slots, as shown in the drawings,

will probably t e found most convenient to or they may be made separatetherefrom. The function of these openings f, f may be performed by meansillustrated in Figs. 6 and 7. When, for example, the table is divided upinto sections each representing results at a different rate per hour,and having a different quarter-hour value, it is desirable that theoperator shall have before him a conveniently exposed indication ofthese values for the particular section of the table upon which he isworking. As shown in Fig. 6, the finder has a small disk or wheel 9rotatably mounted in its edge and movable under two small openings g, 9The disk g has a serrated or milled periphery so that it may be rotatedwith the thumb or finger to bring numbers thereon beneath the openingsg, g. In Fig. 6 the number 16, indicating a'rate per hour, is exposedthrough opening g, and the number 4, indicating the rate per quarterhour, is exposed through opening g Somewhat similar means are shown inFig. 7 for indicating the position of the slots 0 and 7 relative todifierent sections (such as shown in Fig. .5) of a table. A suitabletray (such asA of Fig. 2) has an overhanging flange 11, in which are twoopenings 1" and s. A disk or wheel a; has numbers printed thereonadapted to be displayedthrough openings 1' and 8 according to theposition of finder-slide K. A pinion 'iin engagement with wheel :0 isdriven by a gear wheel 7.", which latter meshes with a rack m, in thepositionrshown the slot 0 is over a 6 cents per hour section of thetable and slot 10 over a 14 cents per hour section thereof.

Having thus described the purely mechanical features of the invention, 1will next explain the improvements relating to the arrangement of thenumbers representing res'ults and factors thereof. 1 Referring first tothe 6% interest table shown in Fig. 1, the numbers 1, 2,3, etc., to 90,arranged in a vertical column at the left, represent days, While thethree horizontal rows of numerals 1 to 9 inclusive, one across the to ofthe table and two across finderslide G adj acent to slots (1 and (1respectively, represent dollars. The numbers representing interest aredisposed in vertical columns beneath the numbers representing dollarsand form horizontal columns with the numbers representing days. Only afew of the interest numbers are shown. To'facilitate locating thedecimal point when the interest on $10., $100.," ii5000., etc. is to beestimated, a space is provided between the second and third and thefifth and sixth digits of each interest number;

In ascertaining the interest, for example, on $359 at6 for 27 days, theoperation is as follows: The finder C is moved until the number 27appears at the left-hand end of slot (1, as shown 1n Fig. S1. By movingthe decimal point two places to the right in the number steers appearingin slot (1 under the 3 on the finder C, I get 61.391507 as the intereston 6300. for the time specified. In a similar manner, by moving thedecimal point one place to the right in the number appearing under 5 onthe finder, I get 6.2219718 as the interest on $50. for the same period.The number 603994521 appearing in the slot under 9 on the slide, is theinterest on $9 for 27 days. These three numbers (1.391507- .2219718and.03994521) equal, when added to ether, $1.65 which is the interest on$359 for 27 days at 6%. In case the numbers representing interest are onthe lower part ofthe table, they are read through slot (1.

The table D, shown in F ig. 4, is divided into sections each comprisingnumbers representing interest at different percentages, and a verticalseries of numbers corresponding to the percentage of each section areplaced at the right-hand edge of the table. By observing these numbersas they appear through openingsflf' the operator is assured that he isreading from the proper section.

As shown in Fig. 5, the device is adapted to the computation of wages.The table is di vided into sections corresponding to different ,ratesper hour, and each section comprises numbers (only a few of which areshown) representing the value of from 1 to 60 hours and half-hours wagesat a given price per hour. The numbers representing results are disposedin horizontal alinement with numranged vertically at the edge of table Dand indicatin hours. They are also disposed in vertical a inem'ent withtwo rows of numbers O1-2etc. to 9, O0l/2l l/2et('. to 9 1/2, extendingacross the finder slide in proximity to the slots 1% and 0,respectively. At the right-hand end of each wage-section the table bearsa series of vertically disposed numbers, as 14,-14-14. representing therate per hour of that section. Each of said numbers has a coefficient,as 3 1 /2, representing the rate of wages per quarter hour. Toillustrate the operation of the device, suppose it is desired toascertain the value of 35 1 /2 hours wages at 18 cents per hour,-thefinder and table .aremoved relatively until the number of hours 30appears in the lefthand end of slot e and the rate per hour 18, appearsin the opening The number $6.39, appearing in the slot 2 beneath the 51/2 above said slot, is the result sou ht. If the value of 35 3/ 4 hoursis sought, t e operator mentally adds the coefficient 4 1/2 cents,apgearing in openinghf, to $6.39. If the numer representing t e resultappears on the lower part of table D, it is read through slot 6. Theconstruction of the device, as well as the arrangement of the numbersmay of course be varied without departing from the nature and principleof the invention. Ra pidity of use may be further facilitat by Iprinting the numbers in contrasting colors through which results numbersand a character in each of the two factor character rows may besimultaneously observed, said finder and table being relatively movablelongitudinally only.

2. A computing device consisting of a table bearing numbers representingmany results disposed in longitudinal and transverse columns or rows,said table alsobearing two longitudinal marginal rows of charactersindicating factors of the results, a finder extending across said tableand having therethrough two relatively distant transverse parallel slotsand an opening at the end of each slot through which results numbers anda character in each of the two factor charac ter rows may be observed,said finder bearing adjacent to each slot a transverse row of otherfactor characters disposed in line with longitudinal rows of the resultsnumbers on the table, andsaid table and finder being relatively movablelongitudinally only.

3. A computing device consisting of a table bearing numbers representingmany results disposed in longitudinal and transverse columns or rows,said table also bearing two longitudinal marginal rows of factorcharacters, each factor character of one row having a coefiicient alsoinscribed upon the table, a finder extending across said table andhaving therethrough a transverse slot and an opening through whichresults numbers and I a character in each of the two factor characterrows may be simultaneously observed, said finder and table beingrelatively movablelongitudinally only.

4. A computing device consisting 01' a table bearing numbersrepresenting many results disposed in longitudinal and trans versecolumns or rows, said. table also bearing two longitudinal marginal rowsof factor char: acters, each factor character of one row hav ing acoefficient also inscribed upon the table, a finder extending acrosssaid table and having therethrough two relatively distanttransverseparallel slots and an opening at the end of each slot throughwhich results numbers and a character in each of the two factorcharacter rows may be'observed, said finder bearing adjacent to eachslot a transverse row of other factorcharacters disposed in line withlongitudinal rows of the results numbers on the table, and said tableand finder being relatively movable longitudinally only.

5. A computing device consisting of a table bearing numbers representingmany results disposed in longitudinal and transverse columns or rows,said table also bearing two longitudinal marginal rows of charactersindicating factors of the results, one row at each side oi the table,and a wide finder extending across said table and having therethroughtwo relatively distant transverse parallel slots separated by acontinuous solid portion of the finder obscuring the table between saidslots, said slots in the finder being of such size as to simultaneouslyexpose a transverse line of results characters and corresponding l actorcharacters in each of the two marginal factor character rows, saidfinder bearing adjacent to each slot a transverse row of other factorcharacters disposed in line with longitudinal rows of the resultsnumbers on the table, and said table and finder being relatively movablelongitudinally only.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses;

CHARLES l/V. DRAPER. VVitne'sses REEVE LEWIS, WM. B. KERKAM.

